#4 Flare #3 Flare Union Black

The AEROQUIP #4 Flare #3 Flare Union Black (FCM5048) is a precision straight adapter fitting designed to connect AN-standard hydraulic lines with different port sizes. This aluminum adapter reduces a 4 AN male port to a 3 AN male configuration, making it essential for hydraulic system modifications where port consolidation or step-down fitting is required.

Constructed from aluminum and finished in black anodized coating, this fitting provides corrosion resistance suitable for diverse operating environments. The flare-to-flare design ensures reliable leak-free connections when properly seated with compatible hoses and adapters. AEROQUIP's engineering meets strict hydraulic system standards, and the straight configuration allows direct line routing without spatial constraints. The lightweight design—weighing just 0.04 lbs—minimizes system weight while maintaining full pressure-rated performance.

This adapter serves applications in automotive cooling systems, mobile hydraulics, industrial machinery, and tactical equipment platforms where AN-standard hydraulic connections are standard. Technicians and system builders choose downsizing adapters like the FCM5048 when consolidating multiple smaller lines into a single larger feed or return line, or when integrating components with mismatched port sizes. The compact 2.3 x 1.1 x 3.75 inch envelope fits tight manifold spaces common in performance and off-road vehicle builds.

AN-standard fittings are the industry benchmark for high-pressure hydraulic assemblies due to their repeatable flare geometry and pressure ratings. A #4 to #3 reducer is a common intermediate step when system architecture requires progressive size changes, and AEROQUIP's proven track record in aerospace and motorsports applications reinforces the reliability buyers expect from this classification.